Look a little closer
Polar bears appear to have brilliant white fur against the snow, but in reality, their fur contains almost no pigment at all. Each hair is a hollow, transparent tube, and it's the scattering of light through these hairs that makes the fur look white.
This is similar to why snow looks white. Snowflakes are made of transparent ice crystals, but because light scatters in many directions as it passes through them, we perceive them as white — and polar bear fur works the same way.
Even more surprising is the color of a polar bear's skin. Underneath the fur, a polar bear's skin is actually close to black, which helps it absorb as much heat from the sun as possible and retain body warmth in brutally cold conditions.
The hollow structure of the fur also acts as insulation, trapping heat and preventing it from escaping. In the end, a polar bear's white appearance is the clever result of transparent fur combined with black skin — an elegant survival strategy.
